I would use less fibers in the tail or antron yarn, even just some stands of uv dubbing. Maybe set the wing back a bit and for a rib just whack off a small piece of different colored thread or floss. Personally I don't really care for biot bodies I tie some and will fish them but I like a fly to last a bit longer. You can get a really cool effect with the ribbing by leaving your tag end of thread long enough to dub a tiny amount of a contrasting color and make nice open even wraps. In the water it really takes on the look of the natural emerging from the shuck.

regarding a wire rib: adding a wire rib will not affect the fly at all. 3-4 turns of of soft copper wire is negligible.

if you really want a rib with no weight: leave a 3-4 inch long piece of thread at the bend of the hook and color it with a dark marker, tie in the tail fibers and wrap the body forward, then spiral wrap the colored thread forward as the ribbing.

regarding the use of biots: get some turkey biots. they are much longer than goose biots. lay them on a moist parer towel prior to tying them in. that helps to soften them and are less prone to breaking/cracking.

I use Turkey biots for my body and coat it with some zap a gap. That will help it last. I would also buy some emerger hooks, but that should be ok. If it doesn't float, try adding some dear hair as the wing and cdc as an underwing. You can also Tue a thin piece of foam as a wing case and it will float for sure. Google "mayhem fly"...that's basically the bow I tie.

Since this fly is an emerger, I would shorten the CDC clump. The wing on an adult mayfly dry is about the length of the hook shank. Your CDC is longer than the emerger nymphal underwater body and is relatively longer than an adult wing would be.

The CDC on your fly should represent the amorphous shape of a body and unfurled wing of the emerging insect; and the larger this shape is, the closer the emerger is to flying off. Also, the larger this shape, the more it should look like the adult. So I think a shorter CDC clump would be more realistic if it were 1/2 to 3/5 its current size.